The Verge has a learned a few interesting things about Google deprecating EAS and how this will affect Windows Phone users. As it turns out, Google informed Microsoft it was planning to remove EAS in the summer of last year, but without giving a firm date. Microsoft has been trying to get a six-month extension from Google, but so far with no luck. In the meantime, Microsoft is also working on adding CardDAV and CalDAV support to Windows Phone - so yay open standards.

However I Don't think they will include it as part of exchange. Exchange is simply a brilliant product and keeping it distinct has the dual effect of enticing new users to its many benefits and keeping them locked in once they switch.

(I have used a number of options professionally and Exchange was so easy, powerful and well supported it became my favourite)

Lack of support for open standards in Exchange server hinders interoperability as much as the lack of support for them in MS client programs. I.e. for example you can't sync your calendar client which works through CalDav with Exchange server. It is especially a problem in corporate environments which are commonly stuck in depending on Microsoft products.